Original Articles The Effect of Vacuum-Assisted Closure in Bacterial Clearance of the Infected Abdomen Ioannis Pliakos, 1 Nikolaos Michalopoulos, 1 Theodossis S. Papavramidis, 1 Stergiani Arampatzi, 2 Eudoxia Diza-Mataftsi, 2 and Spiros Papavramidis 1 Abstract Background: Laparostomy with vacuum-assisted closure (VAC) plays an important role in improving survival in the presence of abdominal infection. We conducted a study of the qualitative changes in the bacterial flora of the peritoneal cavity in patients with severe abdominal infection treated with laparostomy and a VAC device. Methods: Thirty-nine patients with severe abdominal infection treated with abdominal opening and VAC were registered in a clinical study. When an incidence of 53.8% of hospital-acquired peritoneal infection (HAPI) was found in the study patient population, it was decided to divide the patients in two groups according to whether or not they developed a HAPI. The patients’ outcomes were then analyzed. Results: The durations of abdominal opening (p = 0.04), length of stay in the intensive care unit (ICU) (p = 0.01), and of hospitalization (p = 0.04) were significantly greater in patients with HAPI than in those without it, whereas mortality did not differ on the basis of these three variables. Conclusions: Superinfection is common in laparostomy done with a VAC device for managing severe abdominal infection. The data in the present study show that VAC does not alter the quality of the bacterial burden in primary abdominal contamination, nor does it seem to prevent a high incidence of HAPI. However, VAC is as effective in reducing mortality among patients with HAPI as among those without it. S evere sepsis of abdominal origin is defined as sepsis plus organ dysfunction, caused by a condition arising in the peritoneal cavity [1]. The essentials of the management of patients with severe sepsis remain unchanged and can be divided broadly into source control and hemodynamic stabi- lization. Control of sepsis mainly involves surgical explora- tion and temporary or permanent elimination of the infectious agent [2]. Currently, open abdominal treatment remains among the valid approaches to severe abdominal sepsis [3–5]. Topical negative pressure with an abdominal vacuum-as- sisted closure (VAC) device appears to be the optimal means for managing an infected open abdomen [5–10]. This method has several advantages, chiefly related to: (1) The opportunity to close hermetically the abdominal compartment; (2) an easily performed ‘‘second-look’’ laparotomy; and (3) multiple revisions of the abdominal cavity if needed to improve in- fection control [5,8,9,11]. Although evidence-based data are missing, topical nega- tive pressure in patients with severe abdominal infection ap- pears to make a positive contribution to the treatment of these critically ill patients [12,13]. An important issue to be ad- dressed is whether negative abdominal pressure alters the composition of the bacterial population in the peritoneal cavity. We hypothesized that in patients with severe ab- dominal infection treated with the open-abdomen technique, use of a VAC device would reduce the bacterial burden of the abdomen. Patients and Methods To determine whether use of a VAC device would reduce the bacterial burden of the abdomen in patients with infection treated with the open-abdomen technique, we performed a retrospective analysis of a prospectively formed database that was approved by the AHEPA University Hospital Research Ethics Board. The analysis was performed from January 2009 to December 2011. Written informed consent was obtained from the closest relatives of the patients in our study, in accordance with the Good Clinical Practice Guidelines of the International Conference on Harmonisation [14]. The severe 1 Third Department of Surgery and 2 Second Department of Microbiology, Aristotle University of Thessaloniki, AHEPA University Hospital, Thessaloniki, Greece. SURGICAL INFECTIONS Volume 15, Number 1, 2014 ª Mary Ann Liebert, Inc. DOI: 10.1089/sur.2012.156 18